Traditionally, methods are known in which a predetermined projection pattern is projected onto an object to be measured, and the geometry thereof is measured, without making contact with the object to be measured, by analyzing a captured image obtained by imaging the object to be measured, onto which a light beam is projected. JP 2009-094295 A discloses a measurement apparatus for measuring a height of an electronic component based on a captured image obtained by imaging an optical cutting line when line light is projected onto the electronic component.
When a projection pattern is projected onto the object to be measured, multiple reflections may occur, which is light reflection among a plurality of surfaces of the object to be measured. When multiple reflections occur, the captured image may include regions having luminance, which is different from the luminance when there are no multiple reflections, and thus, there is a decrease in the accuracy in measuring the geometry of the object to be measured. In order to prevent such problems, measures have been taken, such as application of an anti-multiple-reflection coating material to the surfaces of the object to be measured or making use of a mask for limiting the region of the object to be measured, onto which the projection pattern is projected.